A layboy of this type is known from German 0S 3 616 470. It is employed to replace the stack without interrupting the supply of sheets to the stacking point. The complete stack can be replaced with no wasted sheets and without the risk of shifting any sheets out of place. The layboy has means of forwarding overlapping sheets to a stacking point, where there is a layoff platform that travels up and down. At the rear of each stack is a separating mechanism that moves up and down and consists of a pivoting arm with a sheet-metal separator on its free end, two jaws, one higher than the other and both capable of moving vertically and in the direction the sheets travel in, and an auxiliary stack platform that can be advanced in the direction of travel and lowered. The separating mechanism that moves up and down can be advanced to the top of the stack, especially between the top sheet on the stack and the overlapping stream, between the rear edges of the sheets. The separating mechanism and the jaws are in the form of a fork or grate and are laterally displaced to allow the jaws to extend through the separating mechanism.
To replace the stack, the jaws enter gaps left by the separating mechanism between the rear edges of the sheets and secure a bunch of sheets, while the auxiliary stack platform travels in or out. The auxiliary stack platform supports the top of the stack while the bottom of the stack is removed.
The layboy disclosed in German OS 3 616 470 is designed for establishing relatively large stacks on pallets. It is not as appropriate for depositing sheets onto a stack when the count is only 500 or 1000 sheets for example because the lower jaw must for reasons of design be relatively far away from the infeed level, which dictates the smallest possible stack.
The principal object of the present invention is to provide a generic layboy that deposits sheets more rapidly onto stacks that are not as high without losing sheets.